1. Field of the Invention
The present invention relates generally to horticulture, and, more specifically, to a coating formulation useful in the root control of plants.
2. Description of the Related Art
It is known to employ chemical formulations for root control of plants for use in construction of containers for plants, and for use in the earth for purposes of providing a barrier to tree roots and the like for concrete sidewalks and building foundations, etc. Present formulations employ elemental copper in a finely divided state or copper compounds. Copper suffers from relatively high cost and unstable price; also, it is relatively environmentally unfriendly.
British Patent document GB 2 110 518 A, published Jun. 22, 1983, describes a bioactive coating and fixing composition useful for spraying or coating plant seeds or plant leaves. The material contains at least one reversibly water-soluble protein of natural origin and at least one non-phyto-toxic salt or complex of various metals, including Zn, Mg, Co, Fe, Mn, Cu, Ti and Mo. The aqueous solution forms, after drying, a water insoluble film which, due to its structure, accelerates and intensifies the germination of seeds. The coating, when applied to plant leaves, such as by spraying, acts as a biocide, protecting against fungus and pests. The compounds of the British Patent are not intended for root control.
U.S. Pat. No. 2,848,842, issued Aug. 28, 1956, to Tennant, Jr., describes a plant container having fibrous walls holding a root inhibitor, such as zinc oxide. Example 2, thereof, describes a mixture of di-beta-naphthyl-p-phenylene diamine, zinc oxide, and neoprene latex to be incorporated within the fibrous walls. The ""842 patent does not teach to use of a coating for root control which is applicable to plant containers and cloth material.
U.S. Pat. No. 3,356,483, issued Dec. 5, 1967 to Leasure, et al., describes the use of divalent heavy metal(including copper and zinc) containing compounds to discourage growth of unwanted plants and fungus. The compounds can also be used, depending on the concentration, to promote plant growth and hasten the maturating and ripening of grain, vegetable, and fruit crops. Also described is the use of the compounds in coatings such as latex paint to protect against mold or mildew. Also, the compounds can be distributed in textiles or cellulosic materials to protect against mildew and rot. The ""483 patent does not describe such compounds in a coating such as with latex paint for use in plant root control.
U.S. Pat. No. 5,526,607, issued Jun. 18, 1996, to Roesch et al. describes a delivery system or device in the form of a cup or pot that delivers biocide or fertilizer. The device comprises a composition that includes cellulose ether, zinc stearate, and cellulose tissue fiber. The ""607 patent does not describe any composition or delivery system for root control of plants.
U.S. Pat. No. 3,582,312, issued Jun. 1, 1971, to Hess et al. describes the use of zinc as a micro nutrient. The ""312 patent does not teach the use of zinc for root control of plants.
U.S. Pat. No. 4,012,503, issued Mar. 15, 1977, to Freiman, describes an anti fouling coating composition for marine use employing zinc oxide as an active component. The ""503 patent does not teach the use of zinc for root control of plants.
U.S. Pat. No. 4,972,627, issued Nov. 27, 1990, to Hori et al. describes a sheet material for cultivating plants, employing elemental zinc or other metal, but does not describe the reason for the use of the metal as being for root control.
U.S. Pat. No. 5,451,242, issued Sep. 19, 1995, to Ming, et al. describes the use of zinc as a micro nutrient in synthetic soils for lunar use, but does not describe zinc as useful for plant root control.
U.S. Pat. No. 6,114,431, issued Sep. 5, 2000, to Lee et al. describes a plastic composition for forming plant containers. The composition contains a copper hydroxide or copper carbonate as an active root control agent. One embodiment of the composition contains up to 5% zinc and/or other nutrient metals in addition to the copper to buffer the toxicity of the copper and provide a more robust plant, but fails to teach the use of zinc in the absence of copper as a root control composition.
The Tatum et al. article teaches the use of a 2% zinc in latex paint composition on cloth for root control of container-grown plants to control the growth of roots through the container wall. The Tatum et al. article fails to teach the use of zinc to prevent root circling.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus, a root control compound solving the aforementioned problems is desired.
The present invention is a root control composition comprising zinc or a compound of zinc, in a latex or other suitable binder or carrier. The composition may be painted, sprayed, injected, or molded into a container or fabric to prevent root circling of ornamental plants. Also, devices that might use this composition include weed barriers, grow bags, mats, nursery containers, nursery pots, and flats. The useful range of compositions is from about 3% to about 28% zinc by weight of zinc compound in a binder or carrier such as latex paint, and the preferred range is about 14% zinc.
Accordingly, it is a principal object of the invention to provide a root control composition for use with plants having a zinc compound as the active ingredient.
It is another object of the invention to provide a root control composition as above having latex paint as a binder or carrier
It is a further object of the invention to provide a root control composition as above which is useful for preventing root circling ornamental plants.
Still another object of the invention is to provide a root control composition as above which provides for a healthier plant with superior root systems than present root control compositions.
Still another object of the invention is to provide methods of manufacture or treatment of nursery pots to provide them with root control characteristics.
It is an object of the invention to provide improved compositions, methods, and articles of manufacture for the purposes described which are inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification.
The present invention is a root control composition comprising zinc or a compound of zinc, in latex or other suitable carrier. The composition may be painted, sprayed, injected, or molded into a container or fabric to prevent root circling of ornamental plants. Also, devices that might use this composition include weed barriers, grow bags, mats, nursery containers, nursery pots, and flats. The present inventive compositions also act as a micro nutrient, in plants, affecting cell elongation while encouraging cell division. Zinc is also useful as a fungicide.
The price of zinc is more stable and less expensive than currently available copper root pruning compositions. The price is related to availability, ease of processing, and environmental friendliness. Taking all of these qualities in consideration, zinc is a more economical product than copper.
The inventive zinc root control composition encourages branching of plant roots, and discourages root circling in containers and plant bags, thus enhancing the growth of ornamental trees, shrubs, and bedding plants.
Other applications of the inventive zinc root control composition include situations where pavement buckling is a problem from roots of plants and root clogging of septic tanks, field lines, buckling sidewalks, and cracking of building foundations. Various formulations of the inventive composition are contemplated for a variety of application needs, depending on factors such as the length of time root control is desired, and the prevailing weather, the composition of the soil, including soil pH, and various nutrients, water alkalinity, and the species of plant to be treated.
The following example illustrates the use of the inventive composition and method of its use.